Wireless communication systems have become an important means by which many people worldwide have come to communicate. A wireless communication system may provide communication for a number of mobile stations, each of which may be serviced by a base station.
As used herein, the term “mobile station” refers to an electronic device that may be used for voice and/or data communication over a wireless communication system. Examples of mobile stations include cellular phones, personal digital assistants (PDAs), wireless modems, laptop computers, etc. A mobile station may alternatively be referred to as an access terminal, a mobile terminal, a subscriber station, a remote station, a user terminal, a terminal, a subscriber unit, a mobile device, a wireless device, user equipment, or some other terminology.
The term “base station” refers to a wireless communication station that is installed at a fixed location and used to communicate with mobile stations. A base station may alternatively be referred to as an access point, a Node B, an evolved Node B, or some other similar terminology.
A mobile station may communicate with one or more base stations via transmissions on the uplink and the downlink. The uplink (or reverse link) refers to the communication link from the mobile station to the base station, and the downlink (or forward link) refers to the communication link from the base station to the mobile station.
A femtocell base station is a small cellular base station, typically designed for use in residential or small business environments. It connects to the service provider's network via broadband (such as DSL or cable). A femtocell base station allows service providers to extend service coverage indoors, especially where access would otherwise be limited or unavailable. A femtocell base station may alternatively be referred to as an access point base station, a Home Node B (HNB), a Home evolved Node B (HeNB), femto node, etc.
The coverage area of a femtocell base station may be referred to herein as a femtocell. The coverage area of a typical base station may be referred to herein as a macrocell, and a typical base station may be referred to herein as a macrocell base station.
Adjacent channel interference is interference caused by extraneous power from a signal in an adjacent channel. Adjacent channel interference may occur between two mobile stations, where one of the mobile stations is receiving service from a femtocell base station and the other mobile station is receiving service from a macrocell base station, and where the two mobile stations are operating at adjacent carriers. The present disclosure relates to reducing adjacent channel interference, particularly where the interfering channels involve a femtocell base station and a macrocell base station.